1971-56 Kbps Modem


Ted Hoff at Intel invents the microprocessor ” a single chip that contained most of the logic elements used to make a computer. Intel's twin innovations with the device were to put most of the transistors that make up a computer's logic circuits on to a single chip and to make that chip programmable. Here, for the first time, according to Robert X. Cringely's book "Accidental Empires," was a programmable device to which a clever engineer could add a few memory chips and a support chip or two and turn it into a real computer you could hold in your hands. Intel's first microprocessor, the 4004, a four bit machine, was released in November, 1971. See 4004. See also Microprocessor.

Floppy disk invented by IBM. It was designed originally to carry the latest IBM mainframe software to mainframe computers, each of which had a floppy drive for the sole purpose of uploading new software. Once the floppies arrived and their software uploaded, they were physically thrown away. It was only later that someone figured you could use floppy disks for permanent storage.

February 8, Trading begins on Nasdaq. Nasdaq stands for National Association of Securities Dealers Automated Quotation or "NASDAQ" System. It started with 2,500 over the counter stocks.

Roy Tomlinson develops a program for sending messages between computer systems. He deisgnates the @ symbol to separate the user name from the computer name in the address. In short, email is invented.

The NAS Report recommended that an equipment certification program could be established to prevent harm to the network caused by hazardous voltages, excessive signal power, improper network control signaling and line imbalance. FCC establishes the PBX and Dialer and Answering Devices Committees to recommend certification standards based on the NAS Report.

Gary Starkweather, Xerox, patents first laser printer. A couple of years later HP and Canon jointly introduce the first commercial laser printers.

FCC establishes the PBX Advisory Committee and the Dialer and Answering Devices Committee and were terminated on the approval of Part 68. The PBX Committee's report was turned over to EIA where it eventually as a voluntary standard, 470. The Dialer and Answering Devices meetings were so contentious that no report was published.

The Intelsat IV communications satellite goes into commercial operation. Initially it has 830 circuits in service and linked ground stations in 15 countries . DUV (Data Under Voice) is introduced. It permits signals to "hitch-hike" on existing microwave radio systems by using the lower end of the frequency band not normally used for voice.


IEEE Communications Society is established on 1 January.

Microwave Communications, Inc, later called MCI, wins an FCC license to transmit calls between Chicago and St Louis.

First commercial video game (Pong) introduced by Nolan Bushnell at Atari.

Email introduced on Arpanet, precursor to the Internet.

IBM announces SNA.

Intel introduces the 8008 microprocessor.

Life, the magazine, unable to compete with TV dies. It followed the death of Look and The Saturday Evening Post.

First computer to computer chat takes place at UCLA.

Jon Postel writes the specifications for Telnet.

The landmark pop-porn film "Deep Throat" starring Linda Lovelace debuts. In December 2002, The New York Times wrote: You don't need to have seen a frame of the movie to be familiar with its ingenious, if ludicrous, premise : a woman is unable to achieve orgasm until a sympathetic doctor discovers that her clitoris resides in her throat. His "treatment" called upon Lovelace to perform hitherto unimaginable feats of fellatio ” the more pleasure her character wants to feel, the more oral satisfaction she has to provide. Having been taught by her husband and manager, Chuck Traynor, to suppress her gag reflex, Lovelace, then in her early 20s, was shown in repeated close-ups following the doctor's advice to lengths that did not seem humanly possible. It was the stuff of which undomesticated male fantasy is made ” the slavish gratification of a carnal desire that had previously been associated only with extramarital license. Small wonder that the 62-minute XXX-rated film, shot in six days by a Brooklyn hairdresser, went on to become astonishingly lucrative. Having been produced with what was, by porn standards, an astronomical budget of $25,000 ( courtesy of Mob backers), the movie racked up at least $600 million in sales. Lovelace was paid $1,200, which she handed over to Traynor.


Computerized Axial Tomography (CAT Scan) invented by Allan Cormack and Godfrey N. Hounsfield.

Ethernet invented by Dr. Robert N. Metcalfe on May 22, 1973 at the Xerox Palo Alto Research Center (PARC). Dave Boggs (Dr. David R. Boggs) was the co- inventor . Metcalfe and Boggs (in that order) were the authors of THE Ethernet paper, published July 76 in CACM. CACM is the Communications part of the ACM. ACM is the Association for Computing Machinery.

Vinton Cerf, computer scientist, invents the basic design of the Internet - the intermediate level gateways (now called routers), the global address space and the concept of end/end acknowledgement .

Gerhard Sessler and James E. West of Bell Labs receive a patent for their unidirectional microphone that improves hands-free telephone conversations.

ARPAnet, the predecessor to the Internet, has 2,000 users. Electronic mail represents three- quarters of its traffic.

Robert Metcalfe invents Ethernet at Xerox PARC. Ethernet uses a cable rather than a radio channel as the transmission medium.

The "Touch-a-matic" telephone is introduced. It can automatically dial a call anywhere in the U.S. at the touch of a single button. Its solid-state memory allows dialing up to 32 pre-coded telephone numbers .

The File Transfer Protocol (FTP) is introduced making it easier to transfer data information.

Reuters introduces the Reuters Monitor, a terminal that allowed banks to display newly deregulated foreign currency rates to traders all around the world. Banks paid to "con- tribute" their rates to the Reuters screens, then paid again to buy the screens themselves and rent an information feed. Reuters added market-moving news. The Reuters Monitor was phenomenally successful.


AT&T introduces Picturephone, a two-way color videoconferencing service at 12 locations around the country. Businesses rented meeting rooms equipped with the technology.

Hewlett-Packard introduces the first programmable pocket calculator, the HP-65. Structured Query Language (SQL) invented by Don Chamberlain and colleagues at IBM Research.

Cerf and Kahn publish "A Protocol for Pocket Network Inconnection" detailing TCP. SMCL invented by Charles F. Goldfarb. First domestic satellites in operation.

AT&T introduces the digital subsriber loop. The Department of Justice files its antitrust suit against AT&T. The Consent Decree, resulting therefrom, required AT&T to divest itself of the 24 Bell Operating Companies by 1984.

Value-added (packet-switched networks) come on the scene. The term "Internet" is used for the first time.


Bill Gates and Paul Allen co-found Micro-soft. Later the hyphen was quietly dropped.

First PCs on sale. MITS Altair 8800 personal computer kit from MITS. The Altair was the first commercially available personal computer kit. It was on the cover of the Popular Electronics January 1975 issue.

Live TV satellite feed. Ali-Frazier fight from HBO (Home Box Office). Sony introduces Betamax, which doesn't do as well as the Video Home System (VHS) introduced later by Matsushita/JVC.

Telephones go mobile. The FCC reallocates a swath of the radio spectrum for mobile communications. Cellular is born.

April 30, Final day of Vietnam War. Saigon falls .

Bolt, Beranek and Newman (BBN) opens Telenet, the first public packet data service. Viking is launched. Lands on Mars in 1976 and sends back data to Earth. Transmission testing begins on the T4M, highest-capacity, short-haul digital transmission system in the U.S. The new system, linking Newark, NJ to New York City, transmits 274 million "bits" of information per second over a single coaxial tube.


First digital electronic central office switch installed.

Apple Computer founded in a Cupertino, CA garage by Steve Jobs and Steve Wozniak. Unix-to-Unix Copy (UUCP) developed at AT&T Bell Labs. Digital radio and time division switching introduced. Alan Shugart, IBM, introduced the 5.25-in floppy. (Much later, in 1987, SONY introduced the 3.5" floppy). Floppies were first introduced with IBM's PCs when they first came on the market in 1981.

The telephone companies support "The Consumers Communications Reform Act of 1976" H.R. 12323, which was endorsed by more than 90 members of the House. This proposed legislation would have retained the telephone companies' monopoly. The FCC counters with its Docket 20003, Economic Implications and Interrelationships Arising from Policies and Practices Relating to Cusotmer Interconnection, Jurisdictional Separations and Rate Structures .Resale and sharing of carrier services permitted. Other Common Carriers (OCCs) now have access to telco Foreign Exchange (FX) and Common Control Switching Arrangement (CCSA) private network facilities.

Centennial of the Telephone. IEEE establishes the Alexander Graham Bell Medal to commemorate of the centennial of the telephone's invention and to provide recognition for outstanding contributions in telecommunications. Amos Joel, William Keister and Raymond Ketchledge are the first recipients.

COMSTAR is launched and begins commercial service. It is in permanent orbit over the Galapagos Islands.

The Cray-1 supercomputer looks like a C-shaped piece of furniture.


First lightwave system installed and begins operation. It's under the streets of Chicago.

Interactive cable system (Qube) installed by Warner Cable. Commodore PET was among the hot PCs of 1977. Hayes introduces 300 bit per second modem for $280. Datapoint introduces Arcnet, a 2.5 megabit per second local area network (LAN) that, at one stage, was the world's largest selling LAN.

Queen Elizabeth II becomes the first head of state to send email. Voyager spacecraft is launched. Sends back signals from Jupiter (1979-1980), Saturn (1981), Uranus (1986) and Neptune (1989).

The Apple II, Commodore Pet and RadioShack TRS-80 debut. They are the first ready- out-of-the-box "microcomputers."


Bell Labs invents cellular technology.

ITU comes out with Group 2 recommendation on fax. Intel introduces the 8086 chip, with 29,000 transistors and processing 16 bits of data at one time. A variation of this chip, the 8088, introduced in 1980, caught IBM's eye and IBM used it in its first PC.

Before enactment of the 1978 law that made it mandatory for dog owners in New York City to clean up after their pets, about 40 million pounds of doggie souvenirs were deposited on the streets of New York City every year.

Airline industry in the United States is de- regulated . Before 1978 the Civil Aeronautics Board set fares, generally allowing the airlines to pass along their costs and to become lazy in the process.

TCP split into TCP and IP.

Usenet established between Duke and UNC by Tom Truscott, Jim Ellis and Steve Bellovin.

TAT-1, the world's first transoceanic telephone cable was retired . Apple II introduced.


Chapter 11 Federal bankruptcy provision introduced. Chapter 11 is court -supervised reorganization. It's put a moratorium on debts , allows the company work a deal with the debtors, try to get the company back on its feet. Chapter 7 is total liquidation. Close the company, sell the assets.

CompuServe Information Service starts and goes on-line. Gordon Matthews invents corporate voice mail. See VMX. A Federal Communications Commission inquiry restricts AT&T from selling enhanced services except through an AT&T subsidiary, American Bell, which begins operations in 1983 and closes down shortly thereafter.

July, Sony introduces its first Walkman, a name which it trademarks. The Walkman plays an cassette, but cannot record. The original Walkman came with two headsets.

Dan Bricklin and Bob Frankston introduce VisiCalc, a spreadsheet program that becomes the PC's first "killer app," or killer application. The spreadsheet, for the first time, showed a practical, business use for the desktop machines. Visicalc's VC.com file occupies slightly less than 28 kilobytes, far smaller than most gif images you see on the Internet.

Gavin Wedell born Sydney, Australia on April 22.


ITU comes out with Group 3 recommendation on fax. Group 3 machines are much faster than Group 2 or 1. After an initial 15-second handshake that is not repeated, Group 3 machines can send an average page of text in 30 seconds or less.

Supreme Court of the United States rules that patents for software can be issued. May 1980, CompuServe becomes a wholly -owned subsidiary of H&R Block, Inc. The Osbourne I makes portable computing practical - for those with strong backs.


IBM introduces its first personal computer August 12 and soon has 75 percent of the market. Its PC uses a Microsoft disk-operating system called PC-DOS (for PC-Disk Operating System). Microsoft is intelligent and keeps the right to a virtually identical operating system called MS-DOS and competitors quickly develop lower-priced PC " clones " running on MS-DOS.

First portable computer, by Osborne.

National electronic phone directory (minitel) starts in France. 3Com introduces the first 10 megabit per second Ethernet adapter. It cost $950. In 1999, you could buy 10 megabit Ethernet adapters for under $30.

France Telecom starts to deploy Minitel.

November. Gerry Friesen and Harry Newton launch Teleconnect Magazine. They sell it in September, 1997 to Miller Freeman, which later becomes CMP Media LLC, which closes the magazine in August 2001. Subscribers receive a magazine called Communications Convergence, the new name for Computer Telephony, a magazine also started by Friesen and Newton.

The Telecommunications Act of the U.K. is passed. It is the first step towards liberalizing the telecommunications market in the U.K. and has four main consequences:

  • The General Post Office (the ernstwhile monopoly provider of telecommunications services in the U.K.) was divided into two separate entities: The Post Office and British Telecommunications (BT), which retained the monopoly over existing telecommunications networks.

  • It determined that a duopoly would be created as a first step towards the introduction of competition in telecommunications.

  • The Secretary of State for Trade and Industry was empowered to license other organizations to be known as Public Telecommunications Operators (PTOs), to operate public telecommunications networks (including cellular networks) in the U.K.

  • It paved the way for the gradual deregulation of equipment supply, installation and maintenance which had previously been the monopoly of the GPO. Following the Act, Mercury Communications, majority-owned by Cable & Wireless was created to compete with British Telecommunications. See also Telecommunications Act of 1981 and 1984.

  • Warner Amex and CompuSereve offer electronic mail to cable TV users in Columbus, Ohio.

Bell Telephone Labs design of a network-embedded database of Personal Identification Numbers (PINs) for calling card customers to be accessed by public telephones over Signaling System 7. (Today, improved architectures of this kind underlie all Intelligent Network services.)

First cellular mobile telephone service is offered , in Saudi Arabia and Scandinavia. A new telephone service, DIAL-ITr allowed a caller to listen to the voice communications between the Space Shuttle Columbia and the ground command center.


The US Postable Service begins an electronic mail service, E-Com, allowing messages to be sent by computer for postal delivery. It's abandoned in 1985.

January 8, the consent decree to break up AT&T into seven regional holding companies and what was left (long distance and manufacturing) is announced. The divestiture takes place two years later on January 1, 1984.

March 3, the FCC formally approves the startup of cellular phone services. The FCC indicated that it would accept applications for licenses in the top 30 markets 90 days after procedures were published and for smaller markets, 180 days after publication. The FCC subsequently gave one license in each market to the local phone company (the "wireline") and one for a competitor (the "non-wireline") carrier.

October 21, the FCC awards the first construction permit for a cellular radio license to AT&T's Ameritech subsidiary (this was prior to the AT&T breakup).

The Katharine Gibb Secretarial Schools teach electronic mail techniques in work processing classes.

The first full-color two-way video teleconferencing service is offered. The development of TFM (Time Frequency Multiplexing). The first compact disk players are available for sale in the U.S.


Novell introduces its first local area network software called NetWare. It was originally introduced to allow a handful of personal computers to share a single hard disk, which at that stage was a costly and scarce resource. As hard disks became more available, the product evolved to allow the sharing of printers and file servers.

Nintendo introduces Famicom, a computer turned video game. Cellular radio in the United States gets its first subscriber. Sony introduces the Camcorder.

October 13, Ameritech turns on its new cellular radio system in Chicago, the first in the nation.

IBM introduces the PC XT, the first IBM PC to contain a hard disk. Bill Gates of Microsoft announces Windows at November's Comdex. IEEE approves 802.3 ” Ethernet local area network. DNS (Domain Name System) introduced on the Internet. DNS is a hierarchical database containing records that describe the name, IP address and other information about hosts . The database residents in DNS servers scattered throughout the Internet and private intranets .

TCP/IP protocol suite mandated for use in the Internet. Name server developed at the University of Wisconsin. April, the Cleaved Coupled-Cavity (C3) laser was introduced. The single frequency tunable laser emitted a light so pure that over a billion bits of information per second could be sent through a glass fiber.


January 2, 1984. The breakup of the Bell System. AT&T gave up its local operating phone companies, which got formed into seven, roughly equal holding companies. In turn, AT&T got the Justice Department off its back for an antitrust suit and got the right to get into industries other than telecommunications. Its chosen industry was the computer industry for which it felt it had unique skills.

The Dot-Com is born. The Domain Name Systems is introduced, classifying network addresses by extensions, like .com.

January 24, Apple Computer Inc.'s Steve Jobs introduces the first Macintosh computer. It was the machine that changed the world of PC computing. Mr. Jobs often described the little machine as "insanely great."

March, Motorola introduces the DynaTAC 8000X, the first portable cellular phone. It listed for $3,995 and weighed two pounds.

Ken Oshman sells Rolm to IBM for $1.26 billion. It was not one of IBM's better investments. Rolm is now part of Siemens, which understands telecommunications.

Prodigy Information Service, a service of IBM and Sears, starts. 1984 Telecommunications Act passed in the U.K. See Telecommunications Act 1981 and 1984.

Local area signaling service is introduced. The service is used to trace nuisance calls, transfer calls, and provide other advanced calling services. (May 20).

AT&T and NASA space shuttle Discover launch its second Telstar 3 satellite.


CD-ROM introduced by Philips and Sony.

Steve Jobs driven from Apple Computer by John Sculley.

John Sculley, head of Apple Computer, licenses the copyrights protecting the "look and feel" of the Apple Macintosh operating system to Microsoft in order to get Microsoft to write more applications for the Mac. The license allowed Microsoft to launch its hugely successful Windows operating system in November of 1985 and to defend itself against a lawsuit brought by Apple alleging Windows was so similar to the Mac that it violated Apple's copyrights.

IBM introduces four megabit per second token ring local area network. Symbolics.com is assigned on March 15 to become the first registered domain.


Novell's SFT NetWare, first fault tolerant local area network operating system.

McDonalds becomes first commercial customer to trial ISDN. It's provided by Illinois Bell.

William G. McGowan, MCI's founding chairman, and a pioneer in the competitive United States telecom scene, has a massive heart attack and a heart transplant . He dies six years later.

MCI Mail, pioneered by Vinton G. Cerf, one of the founders of the Internet, links its mail service with CompuServe, creating a network with half a million subscribers. The services are linked to the Internet in 1989.

SGML becomes an official international standard. See SGML. Network News Transfer Protocol (NNTP) proposed by Brian Kantor and PHil Lapsley. Mail Exchange (MX) records developed by Craig Partridge. The National Science Foundation introduces its 56kbps backbone network. William Esrey elected CEO of of United Telecom, later to become Sprint. In 2003 Esrey was fired as a result of poor performance and amid a scandal of unpaid taxes on hefty options awarded by the board.

Microsoft IPO.


The Year of the Fax Machine, according to the New York Times.

October, 1987, the one-millionth cellular subscriber signs up for service in America. Cable TV reaches the halfway mark, penetrating 50.5% of U.S. homes . George Forrester Colony of Forrester Research is believed to have coined the term "client-server" computing. See Client-Server.

First InterOp trade show, Monterey, California.

Synoptics ships the first Ethernet hub. They progressively get cheaper and cheaper. Archived email is retrieved from the National Security Council computer system in the investigation of the Iran-contra affair.

Perl released by Larry Wall.

Bellcore introduces the Asymmetric Digital Subscriber Line (ADSL) concept which has the potential of multimedia transmission over the nation's copper loops . SONY introduces the 3.5-in floppy. Philip Estridge, IBM, developed the first hard drive for PCs. It held 10MB. N.J. Bell is the first to implement Caller ID.

Superconductivity is discovered - the transmission of electricity without resistance through low temperature material.

TDD (telecommunications device for the deaf) is initiated.


First transatlantic optical fiber cable.

Robert (rob) E. Allen takes over as CEO of AT&T.

The European Union chooses GSM as the general standard for mobile communications, ensuring that even though the 15-nation EU's electrical plugs and TV sets were largely incompatible, at least the cellular phone system across all those nations would be compatible.

IBM speeds up its token ring local area network to 16 megabits per seconds. Wags call token ring a "virtual engagement present."

Computer Emergency Response Team (CERT) formed by DARPA. Internet Relay Chat (IRC) developed by Jarkko Oikarinen. U.S. Congress passes the Telecom Trade Act of 1988 in response to alleged dumping of telecom systems in the U.S. by foreign manufacturers. One aspect was the requirement of all imported telecom equipment to comply with all applicable FCC requirements. Enforcement is by U.S. Customs.


Fiber to the home field trial, Cerritos, CA.

Novell releases NetWare 3.0, the first 32-bit network operating system for Intel 80386/486-based servers.

Panasonic's household- size video phone with moving color images debuts in Tokyo. IETF established. See IETF.

Berlin Wall falls, spelling the effective end of communism, except in North Korea. English computer scientist called Tim Berners-Lee invents the World Wide Web while working at a European nuclear research laboratory.

MP3 is patented.

Tim Berners-Lee proposes a scheme to enable electronic documents to link to other documents stored on other computers. This idea, which later grew into the world wide web, started out as a program called Enquire, which Mr Berners-Lee wrote for his own use while working at CERN, the European Particle Physics Laboratory in Geneva, Switzerland. He went on to write the first web browser and web server, both of which he gave away on the internet, along with details of the protocols to describe and transmit web pages. See also Berners-Lee.


Demonstration of 2,000 kilometer fiber optic link using optical amplifiers without repeaters.

MVIP formed and first product shipped.

Arpanet officially called the Internet.

Sharp introduces the first LCD designed for a laptop and thus the laptop business is launched.

The world (world.std.com) becomes the first commercial provider of Internet dial-up access.

HTTP 1.0 specification published.

The first HTML document published by Tim Berners-Lee. Archie file-indexing system developed.

AT&T filed a petition to strengthen DID rules for prevention of toll fraud. EIA filed a petition to require digital security coding for cordless phones to prevent random dialing that interfered with 911 operations.

Docket 90-313 requiring hotels/motels and coin phones to provide equal access to competing long distance carriers was resolved in 1992.

Digital audiotape (DAT) makes its debut.


AT&T, under chairman Bob Allen, buys NCR for a gigantic $7.4 billion and soon renames it AT&T Global Information Solutions. Later AT&T took hundreds of millions of dollars in restructuring and other charges related to the fact that NCR lost pots of money after AT&T bought it. Part of the problem, according to analysts, was that AT&T bought NCR right at the time NCR was making the transition from traditional mainframe computers to so-called massively parallel computers powered by collections of small, cheaper processors run in tandem. NCR also got hit by a decline in its traditional cash register business as low-margin PCs came in. The skinny around the industry at the time AT&T bought NCR was that AT&T bought NCR to disguise the fact that its own computer operations at that time were losing so much money. And the senior management of AT&T at that time wanted to retire with the glories of booming long distance revenues and not lousy computer results.

Motorola introduces the lightest cellular phone yet, the MicroTAC Lite for about $1,000 retail.

The Electronic Industries Association approves and publishes on July 9, 1991, the Commercial Building Telecommunications Wiring Standard, the most important wiring standard ever published in the history of telecommunications.

Scott Hinton at Bell Labs heads a team that builds the first photonic switching fabric, bringing light-based switching technology in telecommunications networks closer to reality.

Wiltel introduces frame relay service.

Linus Torvalds, a student at the University of Helsinki, invents Linux, a computer operating system that would later go on to become one of the most successful computer operating systems ever created. Torvalds positioned Linux as a "free" operating system, with inputs from programmers all over the world ” but with him as the ultimate decision maker as to which code finally made it to the latest release. Linux rhymes with cynics. See Linux for a much bigger explanation.

World Wide Web created by Tim Berners-Lee at CERN in Switzerland. Gopher released by Paul Lindner and Mark P. McCahill from the University of Minnesota.

On August 29, 1991, the Supreme Soviet, the parliament of the U.S.S.R., suspended all activities of the Communist Party, bringing an end to the institution.


AT&T introduces VideoPhone 2500 marketed as the first home-model color video phone which works on normal dial-up analog phone lines. It meets cool reception because of poor image quality and its high price, namely $1,500. It is later withdrawn from the market.

Microsoft Windows 3.1 and IBM's OS/2 2.0 operating systems introduced. Windows NT (32-bit operating system) debuts in beta form.

Wang files for Chapter 11. Later it emerges from Chapter 11.

MCI introduces VideoPhone for normal dial-up analog phone lines. It retails for $750. It is not compatible with the AT&T video phone. It and the MCI phone promptly bomb and are withdrawn from the market.

The cellular industry signs its ten millionth subscriber on November 23, 1992. At least that's what the press releases said. Some carriers claimed that at year end, cellular subscribers in the United States had actually hit 11 million, way ahead of all predictions .

Apple, EO and others introduce the PDA, the Personal Digital Assistant. Later they called it the Newton.

RMON ratified by IETF.

William G. McGowan, MCI's founding chairman, dies. he suffered a serious heart attack in 1986 and received a heart transplant. He lived for six years with the heart transplant, an absolute miracle of modern medicine. For those of who loved the man, his death was particularly sad.

Congress allows commercial use on the Internet.

Veronica, a Gopherspace search tool, is released by the University of Nevada. The World Wide Web is born - the brain child of CERN physicist Tim Berners-Lee. Congress required all agencies to metricize their rules. A major impact was on Part 68 plug and jack drawings.

Will G. McGowan, chairman and visionary of MCI Communications, dies. United Telecommunicatons changes its name to Sprint.


FCC announces its intention to auction off a chunk of spectrum larger than that used in 1993 for cellular radio. The new airwaves will be used for new types of wireless communications, including portable digital communications devices from phones to laptops, palmtops and PDAs equipped to receive and transmit data of all types, including faxes and video.

Sprint merges with Centel, a local and wireless phone company. Microsoft releases Windows NT.

January, Marc Andreessen and Eric Bina introduce first graphical Web browser called Mosaic. It's from the National Center for Supercomputing Applications.

February 25, McCaw Cellular announces North America's first all-digital cellular service, in Orlando, Florida.

February 26, a bomb explodes in the garage of New York's World Trade Center, killing six people and injuring more than 1,000 others.

March 17, The Clinton administration urges Congress to eschew comparative hearings and institute a lottery for awarding new radio spectrum. See PCS.

August, AT&T agrees to buy McCaw Cellular for $12.6 billion. The idea is to help get AT&T back into local phone service. The company is later spun off as AT&T Wireless.

October, Bell Atlantic sets $21.7 billion merger with TCI, cable TV giant. The assumption is that cable TV and telephone networks are "converging" into an information highway for transporting video, voice and data. The deal later fell apart after the FCC cut cable TV rates and TCI's profitability fell part.

December 31, Thomas J. Watson dies, age 79.

AT&T introduces the AT&T EO Personal Communicator 440, based on the Bell Labs- developed Hobbit microprocessor. This hand-held device combines the features of pen- based personal computers, telephones and fax machines. The device is later withdrawn from the market because of poor demand.

Louis V. Gerstner takes over a stumbling IBM and later turns it around. InterNIC created by NSF.

Telecom Relay Service (TRS) available for the disabled. The National Science Foundation (NSF) network backbone jumps from T-1 to T-3. The world's first 64-bit home console video game system released. Made by IBM, the 'Jaguar' offered high-speed action, CD-quality sound, and polygon graphics processing beyond most other machines available at the time.

The first wireless headset portable CD player is marketed.


The Year of the Internet, according to the New York Times.

GO-MVIP, Inc. formed. Trade association for developers and manufacturers of MVIP computer telephony products.

AT&T pays $12.6 billion for McCaw Cellular Communications Inc. Robert E. Allen is CEO of AT&T. This is his second expensive purchase, the previous one being NCR.

Bill Gates marries Melinda. Later on they have children. Hughes Satellite starts DirecTV, a direct-broadcast satellite service that beams 175 channels to a home satellite antenna dish 18 inches in diameter. It snags 1.3 million subscribers in less than a year.

April 4, Netscape Communications Corp which will go on to create the Navigator version of a browser, is founded. Many date the beginning of the World Wide Web as a serious tool of international commerce to this time.

July 17, Microsoft signs a consent decree with the Justice Department agreeing to give computer manufacturers more freedom to install programs from other companies. As a result, Microsoft slightly alters its licensing contracts.

September 12, Netscape ships its first Internet / Web browser. October 8, A team of six programmers and a veteran Microsoft software developer begin writing the code that will become Internet Explorer version 1.0.

Microsoft licenses technology from Spyglass to help it quickly develop a Web browser. North American Free-Trade Agreement signed by America with Mexico and Canada. Internet is pretty much world-wide with the exception of most of the African interior, Pakistan, Mongolia, Cuba and some areas in South America and Southeast Asia.

Real Audio introduced to Internet which allows one to hear in near real time. Radio HK, the first 24-hr Internet only radio station, starts broadcasting. At the Winter Olympics in Lillehammer, Norway, fiber optics transmitted the first ever digital video signal.


The World Wide Web gets major traction with the creation of Netscape, the first browser of the modern generation. Also Netscape does its IPO ” Initial Public Offering. See also Mosaic.

The first digital video (DV) camcorders are sold. Digital cameras hit the market. Internet traffic grows tenfold in 1995.

IBM buys Lotus for $3.5 billion, the main attraction being Lotus Notes. One of the key attractions of Lotus Notes is that it saves on phone bills by substituting electronic messaging for calling.

May 26, William H. Gates sends his famous "The Internet Tidal Wave" memo to Microsoft's top executives, making the Internet the company's top priority.

Sun introduces Java.

August 24, Windows 95 finally ships. It contains computer telephony features, including TAPI, VoiceView and Fax-on-demand. See TAPI 3.0.

August, Disney agrees to buy Capital Cities/ABC for $19 billion. The idea of the merger was, according to the New York Times, that "biggest is best". The idea was to combine the most profitable TV network with a name-brand family entertainment empire.

August, CBS accepts Westinghouse's $5.4 billion takeover offer. According to the New York Times, the idea of the takeover is that "even an ailing Big 3 TV network is worth owning, if it comes with the collection of radio and TV stations reaching one-third of U.S. households."

September, Time Warner agrees to buy Turner Broadcasting for $7.5 billion. September 20, AT&T announces it will split itself into three companies ” long distance, equipment manufacturing, and computers. Wall Street applauds the decision and in one day lifts the price of AT&T's stock by 10%, or about $6 1/2 billion. Meantime, AT&T announces that it will substantially reduce the size of its failed computer activities, which were called AT&T Global Information Solutions. See 1991.

November, Microsoft ships Internet Explorer 2.0.

December 7, Microsoft publicly unveils its Internet strategy. December 8, Digital Versatile Disk (DVD) is announced. DVD is a specification announced by nine companies for a new type of digital videodisk, similar to CD-ROMs but able to store far more music, video or data in a common format. DVDs will be 5 inches in diameter and will be able to store 4.7 gigabytes on each side, equivalent to 133 minutes of motion picture and sound, or enough to hold most feature-length movies. The companies announcing DVD were Philips, Toshiba, Matsushita Electric Industrial, Sony, Time Warner, Pioneer Electronic, the JVC unit of Matsushita, Hitachi and Mitsubishi Electric.

AT&T announces its plan for restructuring into three separate, publicly traded companies: a services company that will retain the name AT&T; a systems and technology company (Lucent Technologies) composed of Bell Labs, Network Systems, Business Communications Systems, Consumer Products and Microelectronics; and a computer company, which recently returned to the NCR name.

Netscape IPO.


January, After 10 years of trying, Congress finally passes a bill deregulating most segments of the communications industry. Telephone companies, broadcasters and cable operators are all free to enter each other's markets. It's called The Telecommunications Act of 1996. It turns out later to be one of the worst written pieces of Federal legislation in the U.S. See Telecommunications Act of 1996.

Internet traffic doubles again. It had doubled in 1995. One year it doubled in three months. Everybody starts to believe that it will continue doubling every three months forever. The fact that it didn't lead to the tech wreck of 2000, 2001 and 2002.

February, US West signs $5.3 billion deal for Continental Cablevision. The assumption, according to the New York Times, is that it will now have a wire into many homes, by dominating local phone service in 14 states and reaching 16.3 million cable subscribers.

April, SBC Communications (the name for the holding company owning Southwestern Bell Telephone) buys Pacific Telesis (the holding company for Pacific Bell) for $16.7 billion. The assumption of this merger, according to the New York Times, is that regional telephone companies can become national players by combining 30 million phone lines in five states with potential coast-to- coast cellular market of 80 million people.

April, Bell Atlantic buys NYNEX (the holding company for New York Telephone and New England Telephone) for $22.1 billion. The new company will be called Bell Atlantic.

IP Telephony introduced.

Late in the year, Microsoft releases Internet Explorer 3.0. Many reviewers praise its vastly improved nature.

September, Rockwell announced a 56 kbps modem chip set designed for Internet applications. 56K download (PCM); 33.6 upload (analog). Technical committees start development of standards for this new technology. Ccntroversy erupts over the fact the modulation technology limits the theoretical speed to about 53K because of Part 68's signal power limitation requirements to prevent crosstalk to third parties. Actually, because of line impairments the fastest practical speed is around 42 to 44K.

December 30. AT&T spins off NCR, the firm it had bought in 1991 for $7.4 billion. The PalmPilot 1000 launches a handheld revolution. Phone companies began to install 2.5 gigabit fiber-optic equipment.


Amazon.com goes public.

IP Telephony starts to become a reality. Microsoft announces TAPI 3.0, whose cornerstone is IP telephony. See TAPI 3.0.

WorldCom Inc. buys MCI for $30 billion in its own stock for MCI. The offer for $41.50 an MCI share was at a 41% premium over MCI's stockmarket price before the bid was announced. WorldCom later reports accounting irregularities which change later into massive fraud. Along the way it goes bankrupt (Chapter 11) and changes its name ” irony of irony ”to MCI.

The Asian Financial Crisis happens. The Asian markets dropped and most of the Southeast Asian "miracle" economies suffered dramatic reversals. Those economies included Korea, Malayasia, Singapore, Hong Kong and Thailand.

June 12, The U.S and the E.U. reach agreement on mutual recognition of product testing and approval requirements covering everything from lawnmowers, pharmaceuticals , recreational craft to telecom equipment.

October 20, Justice Department files suit against Microsoft alleging that the company violated its 1995 consent decree ” one section of which banned Microsoft from tying the licensing of one product to the acceptance of another.

December 11, Judge Thomas Penfield Jackson issues a temporary restraining order against Microsoft. Microsoft must at least temporarily halt its practice of requiring PC vendors to bundle Internet Explorer with Windows 95 while the case is being decided. Judge Thomas Penfield Jackson also appointed a special master to gather additional evidence. However, Jackson declined to hold Microsoft in contempt ” a move which could have cost Microsoft as much as $1 million a day. He also turned down a Justice Department request to strike down non-disclosure agreements between Microsoft and PC vendors that the department claimed had hampered its attempts to solicit testimony against the software vendor.

Congress mandates that most broadcasters convert to digital signals by 2006 and grants them an estimated $70 billion worth of new television spectrum to do so. But the promise of digital TV ” sharper pictures, better sound, more channels and interactive capability ” has been slow to materialize, with broadcasters and TV makers blaming each other for the sluggish pace of the changeover.

November 1, C. Michael Armstrong is elected chairman and CEO of AT&T, succeeding Robert E. Allen who has been chairman and CEO since 1988.

DVD comes to market.

On August 31, Diana, the Princess of Wales, is killed in an automobile accident in a tunnel by the Seine in Paris.


January 1, 1998. The market for fixed telecommunications services in the EU (European Union) is opened to all competitors. European countries see a proliferation of long distance phone companies.

January 1, 1998. Local service competition becomes a reality in Canada. Local Number Portability (LNP) to be in Canada soon.

February, V.90 56K standard was approved ending months of difficult negotiations and modem wars.

May 18, The Justice Department and 20 states file antitrust suits against Microsoft. May, Galaxy IV satellite messes up, causing 45 million pagers to be shut down and many credit card transactions to cease . The problem was fixed within a few days, but not after lots of publicity.

SBC Communications, Inc. the new name for the regional Bell holding company, Southwestern Bell, agrees to buy Southern New England Telephone Company ” commonly called SNET. See Southern New England Telephone Corporation.

MCI gets bought by Worldcom. New company is called MCI Worldcom. Worldcom paid for the acquisition by issuing paper script it printed itself. And you thought the U.S. government had a monopoly on printing money.

May, Microsoft sued by the U.S. Justice Department for antitrust violations. The Justice Department is later joined by 20 states. A settlement is announced in the fall of 2001.

November 24, American Online agreed to buy Netscape for $4.2 billion. It also made a side agreement to jointly develop technology with Sun Microsystems and Netscape.

Digital Millennium Act Copyright Act passes, making it illegal to circumvent copyright publishing protection technologies.

China tried Lin Hai for plotting against the state by providing 30,000 email addresses to an American magazine. He gets a two-year jail term.

The first digital televisions are sold in the U.S. The DVD-Audio format is agreed upon. Recordable DVD formats emerge. The first portable DVD player is introduced.


January 1, The new European currency called the euro is officially introduced. Eleven European countries have pegged their currency to it. Those countries are Austria, Belgium, Finland, France, Germany, Ireland, Italy, Luxembourg, Netherlands, Portugal and Spain. The euro started at around $US1.17.

Vice President Al Gore admits that he created the Internet. October 4, In the largest corporate takeover deal ever, MCI Worldcom announces that it will acquire Sprint in a stock swap valued at $115 billion.

October 4, Rupert Murdoch sells TV Guide for $9.2 billion. He had bought it for $3 billion in 1987. That was an annual appreciation of about 9.5%.

November 5, Judge Thomas Penfield Jackson issues "findings of fact" showing he believes Microsoft to be a market-stiffling monopoly. No penalty is ordered. That comes later.

Portable MP3 players begin to sell. DVD Audio and SACD players are introduced. Personal video recorders (PVR) are first introduced.

Sprint and WorldCom announce plans to merge in a deal valued at $129 million. The merged was called off the following year in light of regulatory scrutiny.


AT&T's first generation of standardized key telephony system equipment based on a variety of interconnected phone-line-powered relays. Prior to 1A1, key systems were often patched together from a variety of non-standard parts , with varying wiring schemes, making repairs and upgrades very difficult.


An analog central office, made by AT&T and widely deployed by the Bell Operating Companies prior to divestiture.


AT&T's second generation of standardized KEY TELEPHONE SYSTEM equipment. Unlike the phone-line powered 1A1, it used commercial AC power for added features such as illuminated buttons to indicate line status.


AT&T's third generation of standardized KEY TELEPHONE SYSTEMS. It was distinctive for its use of plug-in circuit cards, making it much easier to add features or diagnose and cure problems.


A cute term for an historic TIE electronic key system that provided advanced features, but was priced competitively with 1A2 electromechanical key systems.


Defined in IEEE 802.3, 1Base-5 was the first LAN standard to make use of UTP (Unshielded Twisted Pair). Running at one megabit per second with Manchester encoding, this Ethernet standard operates on a baseband basis, providing for a single transmission at a time. Connection to the centralized hub is accomplished over UTP of 22, 24 or 26 gauge at distances of up to 500 meters in a star topology. Two pairs are used, with one providing upstream connectivity to the hub and the other providing downstream connectivity. AT&T's StarLAN adhered to the 1Base-5 standard, which has long been eclipsed by 10/100Base-T. The maximum segment length for 1Base-5 is 1,640 ft. (500 m). See also 10Base-T and Manchester encoding.


One Business Line, a term used by Bell Canada for a single business phone line.


One Flat rate analog Business phone line. A phone line for which you pay a single monthly charge for and on which you may make as many local phone calls as you wish during that month. A 1FB is an increasing rarity in the United States. See also 1MB.


One Family phone Line, used by Bell Canada to refer to a residential user's phone line.


One Flat rate residential phone line. A phone line for which you pay a single monthly charge for and you on which you may make as many local phone calls as you wish during that month. See also 1MB.

1G Mobile Network

First generation mobile network. Refers to the initial mobile wireless networks that use analog technology only and did not carry data. Advanced Mobile Phone Service (AMPS) is an example of a 1G mobile network standard. See 2G.

1K Pooling

See Number Pooling.


One Message rate Business phone line. A phone line for which you pay a single monthly charge. That charge typically allows you to make a small number of local calls for free. But each additional local call will cost you, either by the minute and/or by the distance, or just by the call. See 1FB.

Slang for a T-1 line. This derives from the fact that a T-1 data line will deliver 1.544 million bits per second.


First National ISDN Signalling System used in Germany. This system is being phased out and will be completely replaced by Euro-ISDN.


The first phase of CDMA2000 technology designed to double voice capacity and support data transmission speeds up to 144 Kbps, or 10 times the speed commonly available today. 1xRTT is compatible with today's IS-95A and IS-95B. IS-95 is Interim Standard 95. IS-95 is a TIA standard (1993) for North American cellular systems based on CDMA (Code Division Multiple Access), and is widely deployed in North America and Asia. IS-95a defines what generally is known as cdmaOne, which supports voice and 14.4 Kbps data rates. IS-95b supports data rates up to 115 Kbps. See also GPRS.

2-6 Code

A 2-6 code is an alphanumeric designation that Verizon uses to identify a trunk group. It consists of two letters and six numbers. An example would be AB-123456.

2-line Network Interface.

Old type interchangeable lightning protectors. The top is painted white to indicate gas type instead of carbon type.

2-way Trunk

A trunk that can be seized at either end.

2-wire Facility

A 2-wire facility is characterized by supporting transmission in two directions simultaneously , where the only method of separating the two signals is by the propagation directions. Impedance mismatches cause signal energy passing in each direction to mix with the signal passing in the opposite direction. See 4-WIRE FACILITY.


Nasdaq tops 5000.

The year of potential computer apocalypse caused by the Millennium Bug, which was meant to bring down computers systems because they had encoded dates at two digits, i.e. 99, instead of four 1999. The crisis never happened . See Y2K for a full explanation.

March 16, 2000, when the Dow Jones industrial average rose nearly 500 points.

April 4. Judge Thomas Penfield Jackson finds that Microsoft violated antitrust law.

June 7. Judge Jackson orders that Microsoft be broken up.

October 25, AT&T announces plans to create four publicly held companies from its current business units:

  1. AT&T Consumer is built around residential long-distance and WorldNet Internet access businesses. It is the U.S.'s largest consumer communications and marketing company.

  2. AT&T Wireless is a cell phone company.

  3. AT&T Broadband is the largest cable TV and broadband services company. It includes AT&T's investments in TCI, MediaOne, and Excite@Home.

  4. AT&T Business combines AT&T's global investments in business communications and services.

DVD recorders begin to sell in the U.S.


The Year of Wireless, according to the New York Times.

September 11, New York's World Trade Center is destroyed . Digital satellite radio enters the market.


January 1, Euro bills and coins go into circulation. Twelve European nations ” Austria, Belgium, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal and Spain ” begin using the new Euro. The currency is also accepted in places like Britain.

January 3, Cable Labs publishes OCAP 1.0 specification. March 14, The FCC classifies cable modem service as an information service, eliminating "forced access" of ISPs on cable operators.

June 26, Adelphia Communications files for Chapter 11. It was the nation's sixth largest cable TV provider.

July 1, National bills and coins of those countries with the Euro as currency are no legal tender. Only the euro is now legal tender. See 1999.

FCC requires the installations of off-air DTV (digital TV) tuners in nearly all new U.S. television sets by 2007.

October 10, FCC declines to approve DirecTV/Echostar merger. November 14, FCC approves $47.5 billion Comcast/AT&T Broadband merger. December 19, Cable and consumer electronics industries reach consensus on how to build "unidirectional, plug and play" cable-ready digital TVs.

Dow Jones Industrials and Nasdaq fall for the third year running. Since the telecom downturn started in the year 2000, 500,000 telecom workers in the United States have lost their jobs. The industry, at the end of 2002, had run up debts of $1 trillion globally and has a huge glut of excess capacity. By some estimates, no additional facilities for distributing telephone calls, data and video around the world (excluding local loops, i.e. the last mile) will be needed until at least 2007.


The number of mobile phones in the world overtakes the number of fixed line phones. There will be 1.47 billion mobile phones, but only 1.41 billion landlines.


On January 20, 2038 the 32-bit signed time_t integer which clocks seconds in UNIX systems will expire. UNIX-based applications and embedded chips, and some other systems based on a 32-bit architecture, count seconds from midnight January 1, 1970, which is the "UNIX Epoch Start Date." On roughly January 20, 2038, the integer will roll over from a zero followed by 31 ones to a one followed by 31 zeros; the system will interpret the date as January 1, 1970. As most application software queries the OS for date information, rather than calculating it internally, the impact of this oversight could be very significant, indeed. Actually, the effect could be felt much earlier. For instance, 30-year mortgages may not be calculated correctly beginning in the year 2008. On the other hand, a UNIX-based system in a restaurant may calculate your check based on the cost of a meal in 1970 dollars-a pleasant thought, although an unlikely result.

214 Licence

Licence from the FCC (Federal Communications Commission) which lets you offer international communications services to customers in the United States.

218-219 MHz

Also known as Interactive Video and Data Service (IVDS). A short- distance communication service designed for licensees to transmit information, product, and service offerings to subscribers and receive interactive responses within a specified service area. Mobile operation is permitted. Federal Communications Commission (FCC) rules permit both common carrier and private operations, as well as one- and two-way communications. Potential applications include ordering goods or services offered by television services, viewer polling, remote meter reading, vending inventory control, and cable television theft deterrence. Until September 15, 1998, the 218-219 MHz Service was known as the Interactive Video and Data Service (IVDS). Many Commission documents still refer to the 218-219 MHz Service by its former name. The FCC has issued a warning that members of the public may receive solicitations to invest in enterprises that hold or plan to acquire licenses in the 218-219 MHz Service. These may still be represented as "IVDS licenses." Entrepreneurs may attempt to use the 218-219 MHz Service licensing process to deceive and defraud unsuspecting investors. Promotional material may promise unrealistic profits, and sales representatives may represent the investment as the "chance of a lifetime." The promotional material may include actual copies of FCC releases, or quotes from FCC personnel, giving the false appearance of FCC approval or knowledge of the solicitation. The FCC does not endorse any individual investment proposal, nor does it provide a warranty with respect to the license being allocated. Obtaining a license is not a guarantee of success in the marketplace . Between 1996 and 1999, many 218-219 MHz Service licenses cancelled automatically due to nonpayment under the terms of the FCC installment payment rules. Furthermore, under the terms of the Report and Order, certain existing licensees may elect to return their licenses to the FCC. You should be aware of these facts when evaluating investment and sales offers in the 218-219 MHz Service. Eighteen 218-219 MHz Service licenses were issued by lottery (random selection) in 1993 by the FCC. The licenses for 9 of the top 10 MSAs were awarded. Two licenses per market were offered for auction at the same time, with the highest bidder given a choice between the two available licenses, and the second highest bidder winning the remaining license. In 1994, the FCC conducted an auction for the remaining MSA licenses that weren't issued by lottery. No RSA licenses have been issued to date. The FCC has no set date for the auction of unallocated 218-219 MHz Service licenses. All licenses are issued for a ten-year term.


An easy way of saying the ISDN Primary Rate Interface circuit. 23B+D has 23 64 Kbps (kilobits per second) paths for carrying voice, data, video or other information and one 64 Kbps channel for carrying out-of-band signaling information. ISDN PRI can be derived from (i.e. channelized out of) a North American T-1 line. In ISDN 23B+D, the one D channel is out-of-band signaling. In T-1, signaling is handled in-band using robbed bit signaling. Increasingly, 23B+D is the preferred way of getting T-1 service since the out-of-band signaling is richer (delivers more information ” like ANI and DNIS) and is more reliable than the in-band signaling on the older T-1. One good thing about PRI: You can now organize with your phone company to deliver the signaling for a bunch of ISDN PRI cards on one D channel. Thus your first line would have 23 voice channels. Your second would have 24 voice channels, etc. Several of the more modern voice cards will accept the signaling for up to eight ISDN PRI channels on the D channel of the first one. See ISDN PRI, Robbed Bit Signaling and T-1.

24-bit Mode

The standard addressing mode of Apple Macintosh's System 6 operating system, where only 24 bits are used to designate addresses. Limits address space to 16MB (2 to the 24th power), of which only 8MB is normally available for application memory. This mode is also used under System 7 (the Mac's more modern operating system) if 32-bit addressing is turned off. See 32-BIT.

24-bit Video Adapter

A color video adapter that can display more than 16 million colors simultaneously. With a 24-bit video card and monitor, a PC can display photographic-quality images.

24- Hour Format

Sometimes known as military time. Using 24 hours to designate the time of day, rather than two, 12 hour segments.


See 24x7.

24th Channel Signaling

See 2G mobile network.


When you see 24x7, it means you're getting something (e.g. service) for 24 hours, seven days of the week. This means you're getting it all the time. 24x7 is a more sexy way of saying "all the time."


The 2500 set is the "normal" single-line analog touchtone desk telephone. It has replaced the rotary dial 500 set in most ” but not all ” areas of the United States and Canada. No one seems to know why the addition of a "2" in front of a model number came to denote touchtone in the old Bell System. Colin Neal, a reader, suggests that the 2 could perhaps have come from 2 (dual)-tone as in DTMF. See DTMF.


See ^.

258A Adapter

A device about 12 inches long and six inches wide and two inches deep that is used to connect a 25-pair Amphenol cable to RJ-45 patch cords.

2600 Tone

Until the late 1960s, America's telephone network was run 100% by AT&T and used 100% in-band signaling, whereby the circuit you talked over was the circuit used for signalling. For in-band signaling to work there needs to be a way to figure when a channel is NOT being used. You can't have nothing on the line, because that "nothing" might be a pause in the conversation. So, in the old days, AT&T put a tone on its vacant long distance lines, those between its switching offices. That tone was 2600 Hertz. If its switching offices heard a 2600 Hz, it knew that that line was not being used. At one point in the 1960s, a breakfast cereal included a small promotion in its cereal boxes. It was a toy whistle. When you blew the whistle, it let out a precise 2600 Hz tone. If you blew that whistle into the mouthpiece of a telephone after dialing any long distance number, it terminated the call as far as the AT&T long distance phone system knew, while still allowing the connection to remain open . If you dialed an 800 number, blew the whistle and then touchtoned in a series of tones (called MF ” multi-frequency ” tones) you could make long distance and international calls for free. The man who discovered the whistle was called John Draper and he picked up the handle of Cap'n Crunch in the nether world of the late 1960s phone phreaks. Since then, in-band signaling has been replaced by outof-band signaling, the newest incarnation being called Signaling System 7. See 2600, Captain Crunch, Multi-Frequency Signaling and Signaling System 7.


The number of words in the Gettysburg Address.


Section 271 of The Telecommunications Act of 1996 describes the conditions by which a Bell Operating Company (BOC) may enter the market to provide interLATA services, long distance in particular, within the region where they operate as the dominant local telephone service provider. The Act mandates that BOCs must open their local telephone markets to competition as a precondition to entry into the long distance market. The term 271 has come to be used as shorthand for referring to the strategic efforts of the BOCs to prove competition exists, and thereby gain FCC approval to provide interLATA long distance service. Although final authority to approve a BOC's entry into the long distance market is given to the FCC, Congress provided in Section 271 a checklist to guide the FCC's assessment of local market competition. The checklist points are (summarized): Interconnection for any requesting telecommunications carrier with the BOC's network that is at least equal in quality to that provided by the BOC to itself. Non-discriminatory access to network elements. Nondiscriminatory access to the poles, ducts, conduits , and rights-of-way owned or controlled by the BOC at just and reasonable rates. Local loop transmission from the central office to the customer's premises, unbundled from local switching or other services. Local transport from the trunk side of a wireline local exchange carrier switch unbundled from switching or other services. Local switching unbundled from transport, local loop transmission, or other services. Non-discriminatory access to 911, directory assistance and operator call completion services. White pages directory listings for customers of the other carrier's telephone exchange service. Nondiscriminatory access to telephone numbers for assignment to the other carrier's telephone exchange service customers. Nondiscriminatory access to databases and associated signaling necessary for call routing and completion. Telecommunications number portability. Nondiscriminatory access to services or information to allow the requesting carrier to implement local dialing parity (the ability to complete a connection without the use of additional access codes). Reciprocal compensation arrangements. Telecommunications services available for resale. See 271 Hearings.

271 Hearings

The incumbent phone company goes before the local public service commission and begs to be allowed to sell long distance phone service. Such hearings are often used by CLECs, who agree to appear and say favorable things, in order to bargain better operating arrangements out of the local phone company. See 271 and CLEC.


A batch standard used to communicate with IBM mainframes or compatible systems.


A shortened way of saying ISDN's Basic Rate Interface, namely two bearer channels and one data channel. A single ISDN circuit divided into two 64 Kbps digital channels for voice or data and one 16 Kbps channel for low speed data (up to 9,600 baud) and signaling. Either or both of the 64 Kbps channels may be used for voice or data. In ISDN 2B+D is known as the Basic Rate Interface. In ISDN, 2B+D is carried on one or two pairs of wires (depending on the interface) ” the same wire pairs that today bring a single voice circuit into your home or office. See ISDN.


Two Binary, One Quaternary. A line encoding technique used in ISDN BRI in the US, and used extensively in the U.S. in first-generation HDSL systems. 2B1Q is a four-level PAM (Pulse Amplitude Modulation) technique which maps two bits of data into one quaternary symbol, with each symbol comprising one of four variations in amplitude and polarity over a circuit. As the resulting signaling rate is half the bit rate, the efficiency of transmission is doubled. In other words, at a given frequency, this 4-level PAM approach allows two bits to be sent per baud (i.e., Hertz, or sine wave). As the rate of signal loss increases as the carrier frequency increases , higher frequency signals attenuate (lose power) more rapidly than do lower frequency signals. Therefore, a method such as 2B1Q allows you to send more data per second using a relatively low frequency. Through the use of 2B1Q, a good-quality twisted-pair local loop can support an ISDN BRI total bit rate of 144 Kbps over a distance of up to 18,000 feet, and without signal repeaters. ISDN BRI operates at a maximum rate of 40 KHz, therefore running at 80 KBaud, which supports a total signaling rate of 160 Kbps. A total of 128 Kbps is used for user payload (two B channels at 64 Kbps each), 16 Kbps for the D channel, and 16 Kbps for framing and synchronization. ISDN BRI uses echo canceling to support full-duplex operation. 2B1Q is described in ANSI T1.601 and ETR 080, Annex A. The line coding technique used in Europe is 4B3T. See also 4B3T, BRI, HDSL, Hertz, ISDN and PAM.


A flat-rate party line with two subscribers.


Two-level Frequency Shift Keying. See FSK for an explanation.

2G Mobile Network

Second generation mobile network. Refers to the second generation cellular phones that introduced digital technology and carried both voice and data conversations. CDMA, TDMA, and GSM are examples of 2G mobile networks. GSM is used throughout the world. CDMA and TDMA are used primarily in the Americas. See GSM and 2.5G.

2G+ Mobile Network

Second generation plus mobile network. Refers generically to a category of mobile wireless networks that support higher data rates than 2G mobile networks. GPRS is an example of a 2G+ mobile network standard.


Two-Wire. See 2-Wire Facility.


Second-and-a-half generation wireless. Refers to the additional features and functionality added to digital cellular phones, such as Internet access and messaging. The main feature added to 2.5G is GPRS, a mobile data communications service running at the speed of a dial-up landline . See GPRS and 3G.


Computer hackers often use the number 3 as a substitute for e.

3:2 Pull-down

A method for overcoming the incompatibility of film and video frame rates when converting or transferring film (shot at 24 frames per second) to video (shot at 30 frames per second).


In Europe, the equivalent of the North American T-1 line is called an E-1. And instead of carrying 1.544 million bits per second, it carries 2.048 million bits per second. This is the rate used by European CEPT carriers to transmit 30 64 Kbps digital channels for voice or data calls, plus a 64 kilobits per second (Kbps) channel for signaling, and a 64 Kbps channel for framing (synchronization) and maintenance. Thus the expression 30B+2D ” 30 B channels for voice (i.e. user information) and 2 D channels for housekeeping ” signaling and maintenance. See E1, E2, E3, and T-1.


The Services Code now available for non-emergency access to police, fire and other governmental departments. The FCC instructed the North American Numbering Plan Administration to make 311 available in order to relieve the load on the 911 emergency number. See also 911 and 711.


IBM's network controller. It connects to the mainframe channel on one end and the LAN media (Ethernet, Token Ring, FDDI) on the other.


IBM's cluster controller. It connects to terminals and other I/O devices on one end, and a mainframe channel on the other.


An adjective that describes hardware or software that manages data, program code, and program address information in 32-bit-wide words. What is the significance of 32-bit? With 32-bit memory, each program can address up to 4 gigabytes (2 to the 32nd power) of memory, i.e. four billion bytes. This is in contrast to Windows 3.x where programs are limited to 16 MB of memory. Possibly more significant than the amount of memory that is available to a 32-bit application is how that memory is accessed. Under Windows 3.x, memory is accessed by using two 16-bit values that are combined to form a 24-bit memory address. (24-bits is the size of the memory addressing path of the Intel 80286. The 80286 is the architecture that Windows 3.x was designed for.) The first 16- bit value (selector) is used to determine a base address. The second 16-bit value (offset) indicates the offset from the base address. One of the side effects of this architecture is that the maximum size of a single chunk of memory is 64 KB. Windows 95 and Windows NT are 32-bit operating systems. Windows 95 and Windows NT developers can address memory with a single 32-bit value. Such an addressing scheme allows developers to view memory as one flat, linear space with no artificial limits on the size of a single segment. No longer are programmers concerned about selectors and offsets and the 64 KB segment limit. Also, Windows 95 and Windows NT take full advantage of the protection features of the Intel 80386 microprocessor. 32-bit applications are given their own protected address space which tends to prevent applications from inadvertently overwriting each other.

32-bit Addressing

See 32-BIT.

32-bit Computer

A computer that uses a central processing unit (CPU) with a 32- bit data bus and central processing unit (CPU) which processes four bytes (32 bits) of information at a time. Personal computers advertised as 32-bit machines ” such as Macintosh SE, and PCs based on the 80386X microprocessor ” aren't true 32-bit computers. These computers use microprocessors (such as the Motorola 68000 and Intel 80386SX) that can process four bytes at a time internally, but the external data bus is only 16 bits wide. 32-bit microprocessors, such as the Intel 80386DX, the Pentium and the Motorola 68030, use a true 32-bit external data bus and can use 32-bit peripherals. See also 64-bit processor.


IBM class of terminals (or printers) used in SNA networks.

3270 Gateway

An electronic link which uses 3270 terminals to handle data communications between PCs and IBM mainframes.


A specific variation of IBM's System Network Architecture for controlling communications between a 3270 terminal connected to an IBM mainframe.


IBM series of Control Units or Cluster Controllers provide a control interface between host computers and clusters of 3270 compatible terminals.


Belonging to IBM's 3270 collection of data communications terminals.


A communications device for an IBM mainframe computer.


The type of fixed function computer terminals used with IBM mainframe computers.

370 Block Mux Channel

See Block Multiplexer Channel.


IBM's communications controllers, often called front-end processors. 3745 devices channel-attach to the mainframe and support connections to LANs and other FEPS.


A batch protocol used to communicate with an IBM mainframe or compatible system.


A UNIX-based minicomputer, manufactured by AT&T and widely deployed by the Bell Operating Companies prior to divestiture.


3D Application Programming Interface. This generic term refers to any API that supports the creation of standard 3D objects, lights, cameras, perspectives, etc. APIs include Argonaut's BRender and Microsoft's Reality Lab.


3-D Geometry File. A platform independent format for exchanging 3-D geometry data among applications. Developed by Macromind.


A flat-rate party line with three subscribers.


Third Generation Mobile System. The generic term for the next generation of wireless mobile communications networks. Most commonly 3G networks are discussed as graceful enhancements of the GSM cellular standards. Thereby, existing GSM networks can be upgraded on a non-disruptive basis. The enhancements include greater bandwidth, more sophisticated compression techniques, and the inclusion of in-building systems. 3G networks will transmit data at 144 kilobits per second, or up to 2 megabits per second from fixed locations. This planned evolution of GSM is an integral part of the ITU-T's vision of IMT-2000 (International Mobile Telecommunications for the year 2000), which clearly will miss the target date of 2000.

3G will standardize three mutually incompatible standards: FDD, TDD, and CDMA2000. FDD and TDD are extensions of GSM architecture using CDMA technology in the air interface. CDMA2000 is the extension of IS95 air interface for wideband data applications. The three standards will compete with each other in the marketplace. In addition to the technical differences between the standards, there is a strong political background in the competition. FDD and TDD were proposed by European firms, and will be promoted worldwide as the heirs to GSM systems. CDMA2000 was the standard championed by Qualcomm, the USA based company with many patents in CDMA technology. See 3GPP, 4G, CDMA2000, FDD and TDD.


Third Generation Partnership Project. The Organizational Partners comprise ARIB (Association of Radio Industries and Businesses) of Japan, CWSI (China Wireless Telecommunication Standard group), ETSI (European Telecommunications Standards Institute), T1 (Standards Committee T1 Telecommunications) sponsored by ATIS (Alliance for Telecommunications Industry Solutions) and ANSI (American National Standards Institute), TTA (Telecommunications Technology Association) of Korea, and TTC (Telecommunication Technology Committee) of Japan. The partners have agreed to cooperate for the production of Technical Specifications for a 3rd Generation Mobile System based on the evolved GSM core networks and the radio access technologies that they support. The TSG (Technical Specification Group) addressing the GSM evolution is known as GERAN (GSM/EDGE Radio Access Network). www.3gpp.org and www.etsi.org. In November 2000, 3GPP announced working relationships with the International Telecommunication Union (ITU) and the Internet Engineering Task Force (IETF). See also EDGE, GPRS, and GSM.


The second phase of cdma2000 technology expected to offer speeds up to 384 Kbps for mobile and 2 Mbps for stationary applications. 3xRTT offers greater capacity (i.e., three 1.25 MHz carriers) than current CDMA systems (one 1.25 MHz carrier).

4 Million English Pounds

Four million English pounds was the amount King Fahd of Saudi Arabia is expected to spend per day while on holiday in the summer of 2002 at his palace on the Costa del Sol in Spain. according to the magazine, Money Week. The king brought with him three planes full of helpers and hospital equipment in addition to his customized 747. A local florist is to supply the palace with 1,000 English pounds of fresh flowers per day. 500 mobile phones have been ordered and a local department store has set up a direct line of credit and will stay open round the clock to satisfy any whims. Some of the money is being spent in London, where an escort agency has been contracted to supply blond companions to make the visitors feel at home.

4-wire Facility

A 4-wire facility supports transmission in two directions, but isolates the signals by frequency division, time division, space division, or other techniques that enable reflections to occur without causing the signals to mix together. A facility is also called 4-wire if its interfaces to other equipment meet this 4-wire criteria (even if 2-wire facilities are used internally), as long as crosstalk between the two transmission directions, as measured at the interface, is negligible. See 2-WIRE FACILITY.


No regional Bell Operating Company is presently allowed to own more than 4.9% of the stock of a telecommunications manufacturing company. See Divestiture.


Four to three is the ratio of width to height in a traditional TV set. The newer high definition TV sets have a 16:9 ratio. That makes them much more rectangular.


The world's first general-purpose microprocessor (computer on a chip). The 4004 was made by Intel, was 4-bit, was released on November 15, 1971 and contained 2,300 transistors. It executed 60,000 instructions per second. The tiny 4004 had as much computing power as the first electronic computer, ENIAC, which filled 3,000 cubic feet with 18,000 vacuum tubes when it was built in 1946. The 4004 found a home in desktop calculators , traffic lights and electronic scales . Despite its power, its 4-bit structure was too small to process all the bits of data at one time to handle all the letters of the alphabet. It was followed by the 8-bit 8008. See also 1971 and 1978.


A shortened way of saying 40 gigabit per second transmission technology. See SONET.


When a page on a web site is removed, the server will automatically generate a 404 error message when a visitor attempts to view that page.


The local number dialed for local directory assistance (we used to call it Information) in many, but not all, cities in North America. Sometimes you have to dial 555-1212. Sometimes you have to dial 1-555-1212. For long distance directory assistance, you would dial 1-213-555-1212 (for information in the 213 area code). See also N11.


AT&T's specifications for its ISDN PRI (Primary Rate Interface). It is different from the ANSI standard T1.607.

419 Scam

A fraud, particularly one originating in Nigeria, in which a person is asked for money to help secure the release of a much larger sum and is promised a piece of the larger sum. The classic 419 scam asks the victim to help some hapless relative of a deposed despot get millions of dollars out of the con artist's country. The con artist offers the victim a percentage of this illusive pot of gold, hoping to suck the victim into paying all sorts of fees to get trunks of money out of Nigeria, Sierra Leone, the Philippines or whatever exotic locale the con artist chooses. In the end, the money is never sent, but the victims are often out thousands of dollars. 419 refers to the relevant section of the Criminal Code of Nigeria.


A famous old Bell System tool which many installers found very convenient to hold a diminishing marijuana cigarette ( called a 'roach') in the 1960s.


An early terminal block. The Model 42A is a plastic mounting base about two inches square with four screws and a cover. Before modular connections became widespread, the 42A was used to connect a phone's line cord to the wire inside a wall or running around the baseboard . Adapters, such as the No. 725A made by AT&T and Suttle Apparatus, can be used to convert a 42A into a 4-conductor modular jack. See also Terminal Block.


The area code, or Numbering Plan Area (NPA), used to identify certain carrier-specific services. The specific carrier is identified by the succeeding NXX, which is the next three digits. This number is used to ensure proper routing of inbound international calls destined for these services into and between North American Numbering Plan (NANP) countries. Current NXX assignments include 226 or Teleglobe Canada, 228 and 229 for AT&T, 624 for MCI, and 640 for Sprint.


In North America, most cordless phones operate within the band 46-49 MHz. That band contains only 10 channels and is horribly overcrowded. Recently, the FCC authorized a new frequency range ” 905-928 MHz ” for use by, amongst other things, cordless phones. The 900 Mhz contains 50 channels.


The last generation of "telco-quality" add-on speakerphones, with separately-housed microphone and speaker; made by both Western Electric (AT&T) and Precision Components, Inc.

4B/5B Local Fiber

4-byte/5-byte local fiber. Fiber channel physical media used for FDDI and ATM. Supports speeds up to 100 Mbps over multimode fiber. See also TAXI 4B/5B.


4 Binary 3 Ternary. A line coding technique used in Europe and elsewhere to support ISDN BRI (Basic Rate Interface). A "block code" that uses "Return-to-Zero" states on the line, 4B3T combines 4 bits to represent one ternary (i.e., one of three) signal state on the line. Therefore, 4B3T supports a total signaling rate of 160 Kbps at a baud rate of 120 KBaud. The three signaling states presented to the ISDN BRI line are a positive pulse (+), a negative pulse (-), and a null pulse (zero-state, or 0). 4B3T is defined in ETR 080, Annex B, and various national standards. The corresponding line coding technique used in the US to support ISDN BRI is 2B1Q. See also 2B1Q and BRI.


4 Bits 5 Bits. A Manchester data encoding/decoding scheme that encodes four data bits into a 5-bit transmission sequence. 4B5B is used in 25 Mbps ATM, as well as 10Base-T and certain 100Base-T (100Base-TX and 100Base-FX) implementations . With 4B5B, the data octets within the data frames to be transmitted over the serial (i.e., one bit at a time) link are divided into 4-bit nibbles (Note: A 4-bit value is known as a nibble, which is exactly half of an 8-bit byte. I kid you not.). Each nibble is then scrambled, using a standard scrambling algorithm, and is mapped into a 5-bit sequence prior to transmission. The 5-bit sequence includes bits for delineation of the data sets, and control indicators for clock recovery (i.e., synchronization at the receiving end of the transmission) and data recovery (i.e., error control). As 4B5B uses a NRZ (Non Return to Zero) unibit (i.e., one bit per baud, or one bit per Hertz) signaling scheme, a 100Base-T application requires aggregate bandwidth of 125 MHz to support transmission of 100 Mbps. See also 5B6B, 8B6T, 8B10B, 10Base-T, 100Base-T, ATM, and Manchester.


A digital central office switching system made by Lucent. It is typically used as an "tandem switching office, switching long distance phone calls. See 5ESS.


A flat-rate party line with four subscribers.


Four-level frequency shift-keying. See FSK for an explanation.


4G is what the next, next generation cellular might be. The idea is simple ” universal high-speed Internet access. The thinking is WiFi Internet access (at up to 10 megabits per second) with blanket coverage and fewer base stations than are needed in today's cell phone networks. Firms including IPWireless, Flarion, Navini, ArrayComm and Broadstorm offer just such a blend. But these are proprietary solutions, so far. Such proposed 4G wireless-broadband systems can be seen in two ways: as a rival to coffee shop WiFi or as a wireless alternative to the cable modem and digital subscriber line (DSL) technologies that now provide broadband access to homes and offices. IPWireless sees their system as a fast internet connection that follows you around. Navini calls it "nomadic broadband"; ArrayComm's term is "personal broadband". Mike Gallagher of Flarion, a firm backed by Cisco, likens WiFi to cordless phones that work within a limited range of a base- station, whereas 4G is akin to mobile phones that work anywhere. Advocates of 4G technology argue that, unlike with 3G and WiFi, the business case for 4G is sound. Nobody is sure how commercial WiFi hotspots will make money. The number of connections per day at most hotspots is still tiny. But 4G is being priced like fixed-line broadband, a service for which millions of users worldwide are already willing to pay about $50 a month. 4G networks may be built initially in regions where cable and DSL are unavailable, in order to capitalize on pent-up demand for broadband. Some cell phone companies are said to be considering skipping 3G altogether in favor of 4G,


Fourth Generation Language.


Four wire.


Four Wavelength Wave Division Multiplexing, also called Quad-WDM. MCI announced this technology in the Spring of 1996 as a method of allowing a single fiber to accommodate four light signals instead of one, by routing them at different wavelengths through the use of narrow-band wave division multiplexing equipment. The technology allowed MCI to transmit four times the amount of traffic along existing fiber. At that time MCI's backbone network operated at 2.5 gigabits per second (2.5 billion bits) over a single strand of fiber optic glass. Using Quad-WDM the same fiber's capacity will rise to 10 gigabits ” enough capacity to carry 64,500 simultaneous transmissions over one single strand of fiber.

500 Service

A non-geographic area code specifically assigned for Personal Communications Services (PCS), as originally defined ” in other words, not necessarily the cellular-like PCS we hear so much about. 500 numbers provide for follow-me services, which allow the subscriber to define a priority sequence of telephone numbers which the network will use to search for him. For instance, the search might begin at your business phone, progressing to your cellular/PCS phone, then to your home phone, and then to your voice mailbox, assuming that you can't be found or don't want to be found. Options might include distinctive ringing for pre-defined callers of significance such as your spouse, significant other, or boss. Further options might include billing, such as caller pays any long distance charges (hopefully, with pre-notification), call blocking, and selective call blocking. 500 Service promises to offer a single telephone number which can find you anywhere, for life. All available 500 numbers were assigned in 1995; plans exist to expand 500 Service area codes, to include area codes such as 520 and 533. 500 Services, clearly, are network-based. CPE solutions recently have emerged, as well. See also Wildfire.

500 Set

The old rotary dial telephone deskset. The touchtone version was called a 2500 set.


501(c)(3) refers to the specific section of the Internal Revenue Code that designates a tax-exempt organization. Such organizations are required to be nonprofit and must reinvest their revenues back into the organization. They are also, for the most part, public entities subject to oversight by the IRS (Internal Revenue Service) to ensure compliance with very stringent regulations. If you give money to an organization which has 501(c)(3) status, you can be assured that your donation will be allowed by the IRS as a deduction from your income. To be 100% sure, you need to make sure that the entity has the IRS approval. And the way to do that is to get a copy of the letter from the IRS authorizing grant of the 501(c)(3) exemption status to the charity you're giving money to.


FCC designated local phone number in the United States for traveler information.


IBM class of terminals for midrange (System 3x and AS/400) environments.

5250 Gateway

An electronic link which uses 5250 terminals to handle communications between PCs and IBM minicomputers.


Central office prefix numbers used to access a wide variety of information services. 555 numbers are in the format 555-XXXX. For example, you dial dial 411 for local Directory Assistance (we used to call it Information) in many, but not all, cities in North America. Sometimes you have to dial 555-1212. Sometimes you have to dial 1-555- 1212. If you want to double-check to make absolutely sure of the identity of your IXC (Interexchange Carrier), to make sure that you haven't been "slammed," you can dial 1- 700-555-4141. Many Hollywood movies use phone numbers like 213-555-5678, knowing that they won't be some real person's number. See also 700, and Slamming.

56 Kbps

A 64,000 bit per second digital circuit with 8,000 bits per second used for signaling. Sometimes called Switched 56, DDS (Digital Data Service) or ADN (Advanced Digital Network). Each carrier has its own name for this service. The phone companies are obsoleting this service in favor of the more modern ISDN BRI, which has two 64 Kbps circuits (called Bearer circuits) and one 16 Kbps packet circuit. See 56 Kbps Modem, K56flex and ISDN.

56 Kbps Modem

Technically known as a V.90 modem, a 56 Kbps modem is the fastest speed modem currently available that will work on normal dial-up analog phone lines. The basics of the technology can be attributed to Brent Townshend, an independent inventor. V.PCM and V.fast were the working names used while the ITU-T was in the process of finalizing the standard V.90 standard. Previous to the development of the ITUT standard, there were two competing, non-compatible 56 Kbps modem pseudo-standards ” x2 and K56flex. All 56 Kbps modems are asymmetric, i.e., they operate at a higher signaling rate in one direction than in the other. Specifically, they provide a maximum of 56 Kbps downstream and 33.6 Kbps (V.34+ speed) upstream. While that may seem odd, it's about the best you can do with a modem running on an analog phone line. The asymmetric nature of 56 Kbps modems is justified thus: When you're on the Internet or your corporate Intranet, most of the bandwidth you need is for downstream transmission (i.e., information flowing at you). You need this speed to download graphics-intensive (read bandwidth-intensive) files or large bandwidth- intensive files (e.g., updates to your software). Upstream you typically transmit only a few keystrokes or mouse-clicks (i.e., instructions to retrieve the information), or perhaps a textual e-mail, which does not involve a lot of bits and bytes. Even if you're transmitting an e-mail with a large attachment (e.g., a PowerPoint file), 33.6 Kbps generally is not a big issue, as it's the best you were able to achieve with the predecessor V.34+ modems, anyway. 56 Kbps modems are able to achieve this minor miracle by virtue of the fact that today's PSTN is largely digital; in fact, they depend on the PSTN's digital nature.

56 Kbps modems work like this. The user installs a 56 Kbps modem on his PC or laptop, which connects to the PSTN via an analog local loop. The serving central office must be digital, as must be the entire carrier network(s), as must be the terminating central office, and as must be the local loop connection (T-1 or ISDN) to the terminating location (e.g., corporate Intranet site or ISP, Internet Service Provider). Matching 56-Kbps technology must be in place at the terminating location, typically in the form of an access router or switch. As the transmissions must suffer only one A-to-D ( analog-to-digital ) conversion process, the potential amount of quantizing noise is limited and the higher speeds can be supported with a satisfactory level of error performance. As the PSTN uses PCM (Pulse Code Modulation) for voice-grade A-to-D conversions, the theoretical transmission speed limit is 64 Kbps. It is assumed that somewhere in the circuit-switched PSTN an older channel bank will be involved and, therefore, bit robbing will consume 8 Kbps for signaling and control, thereby limiting effective signaling speed to 56 Kbps. The U.S.'s Federal Communications Commission effectively set a limit on the speed of 56 Kbps modem by regulating the maximum power of the signal transmitted, which in effects puts a limit on speed. The FCC's mandated power limit of -12dBm ” about 63 microwatts ” for phones was set to prevent interference or noise bleeding into adjacent phone lines. Imagine trying to talk while loud rock music is playing nearby. At that upper power limit, the maximum attainable speed with a 56 Kbps modem is thus about 53.3 Kbps ” though there are now rumbles to beg to the FCC to remove this restriction.

The actual transmission speed depends on the quality of your analog local loop. The performance of the local loop is sensitive to anomalies such as bad splices, bridge taps, and poorly insulated splice casings. Additionally, transmission speed is affected by EMI (electromagnetic interference) caused by electrical storms, radio transmissions and other sources of electromagnetic energy. Finally, other transmissions taking place on twisted pairs in proximity to your pair in the same cable may affect transmission speed. In other words, 53.3 Kbps is the maximum, rather than the norm. Published surveys of 56 Kbps modems show typical achieved transmission speeds of between 40 Kbps and 46 Kbps. I achieve around 48 Kbps on my dial-up phone line in New York City and around 44 Kbps at my phone line in midstate New York (the Albany area). Ray Horak, my Contributing Editor, never got better than 40 Kbps at his previous residence. Then he moved to a new house (actually a very cool, restored 1909 farmhouse), where he had to bury his own drop from the cable pedestal to the house. (Actually, he didn't have to, but Verizon wanted $6.00 a foot to bury a drop. As the drop needed to be about 250 feet, Ray figures he saved $1,500, which isn't a bad payday for 6 hours of work with a shovel.) Ray buried 10 pairs. He now gets reliably gets performance of 50 Kbps.

56 Kbps modems are also V.34 and V.34+ modems. Assuming that the terminating modem is V.34+ (and it often is), the 56 Kbps modem will "fall back" to that standard, which supports symmetric transmission at 33.6 Kbps. Until the ITU-T came out with V.90, there were two competing pre-standard solutions ” x2 and K56flex. x2 was developed by US Robotics. K56flex was developed by Rockwell Semiconductor and Lucent Technologies. x2 was not compatible with K56flex. Neither x2 nor K56flex conform to V.90. Though some of these modems x2 and K56flex modems are upgradeable to V.90, most are not. See also K56flex, 56 Kbps Modem, V.90, V.91, V.92, and V.PCM.

Newton[ap]s Telecom Dictionary
Newton[ap]s Telecom Dictionary
ISBN: 979387345
Year: 2004
Pages: 133

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